Technique for flowrate calculation of cryogenic two-phase flows in Venturi flowmeters without separation

2020 ◽  
pp. 34-42
Author(s):  
I.A. Arkharov ◽  
I.D. Kakorin
Keyword(s):  
Equation Of State ◽  
Pressure Drop ◽  
Measurement Range ◽  
Two Phase Flows ◽  
Two Phase ◽  
Optimal Measurement ◽  
Flow Parameters ◽  
Phase Medium ◽  
Vapour Quality ◽  
Cryogenic Flows

A technique for calculating the flowrate of cryogenic two-phase flows in separationless flowmeters based on a venturi is proposed. The technique takes into account the equation of state of the two-phase medium, that is changes in density, mass vapour quality and temperature of cryogens two-phase flows against pressure in the venturi. It is shown that without an accounting of the flow parameters evolution, an additional flowrate error appears and therefore it is impossible to correctly determine the sensitivity and measurement range of the flowmeter. The most optimal measurement range of the pressure drop is chosen as well as a method of the flowrate measuring by the temperature difference across the venturi is proposed. The problem of determining the flowrate of two-phase cryogenic flows is topical for accelerator, aerospace and gas-transport engineering.

Frictional pressure drop analysis for horizontal and vertical air-water two-phase flows in different pipe sizes

2018 ◽  
Vol 332 ◽  
pp. 147-161 ◽  
Author(s):  
Cihang Lu ◽  
Ran Kong ◽  
Shouxu Qiao ◽  
Joshua Larimer ◽  
Seungjin Kim ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Two Phase Flows ◽  
Two Phase ◽  
Frictional Pressure Drop

Friction Factor Equations Accuracy for Single and Two-Phase Flows

2020 ◽  
Author(s):  
Germano Scarabeli Custódio Assunção ◽  
Dykenlove Marcelin ◽  
João Carlos Von Hohendorff Filho ◽  
Denis José Schiozer ◽  
Marcelo Souza De Castro
Keyword(s):  
Pressure Drop ◽  
Friction Factor ◽  
Single Phase ◽  
Computational Cost ◽  
Two Phase Flows ◽  
Two Phase ◽  
Explicit Equation ◽  
Implicit Equation ◽  
Lower Accuracy ◽  
Statistical Metrics

Abstract Estimate pressure drop throughout petroleum production and transport system has an important role to properly sizing the various parameters involved in those complex facilities. One of the most challenging variables used to calculate the pressure drop is the friction factor, also known as Darcy–Weisbach’s friction factor. In this context, Colebrook’ s equation is recognized by many engineers and scientists as the most accurate equation to estimate it. However, due to its computational cost, since it is an implicit equation, several explicit equations have been developed over the decades to accurately estimate friction factor in a straightforward way. This paper aims to investigate accuracy of 46 of those explicit equations and Colebrook implicit equation against 2397 experimental points from single-phase and two-phase flows, with Reynolds number between 3000 and 735000 and relative roughness between 0 and 1.40 × 10−3. Applying three different statistical metrics, we concluded that the best explicit equation, proposed by Achour et al. (2002), presented better accuracy to estimate friction factor than Colebrook’s equation. On the other hand, we also showed that equations developed by Wood (1966), Rao and Kumar (2007) and Brkić (2016) must be used in specifics conditions which were developed, otherwise can produce highly inaccurate results. The remaining equations presented good accuracy and can be applied, however, presented similar or lower accuracy than Colebrook’s equation.

Experimental Investigation on Flow Patterns and Frictional Pressure Drop of Downward Air-Water Two-Phase Flow in Vertical Pipes

2013 ◽  
Author(s):  
Yuqing Xue ◽  
Huixiong Li ◽  
Tianyou Sheng ◽  
Changjiang Liao
Keyword(s):  
Pressure Drop ◽  
Flow Pattern ◽  
Oil Recovery ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Phase Flow ◽  
Vertical Pipe ◽  
Two Phase Flows ◽  
Two Phase ◽  
Frictional Pressure Drop

A large amount of air need be transported into the reservoir in the deep stratum to supply oxygen to some microbes in Microbial Enhanced Oil Recovery (MEOR). Air-water two-phase flows downward along vertical pipeline during the air transportation. Base on the experiment data described in this paper, the characteristics of air-water two phase flow patterns were investigated. The flow pattern map of air-water two phase flows in the pipe with inner diameter of 65 mm was drawn, criterions of flow pattern transition were discussed, and the dynamic signals of the pressure and the differential pressure of the two phase flow were recorded to characterize the three basic flow regimes indirectly. The frictional pressure drop of downward flow in vertical pipe must not be disregarded contrast with upward two phase flow in the vertical pipe because the buoyancy must be overcame when the gas flows downward along pipe, and there would be a maximum value of frictional when the flow pattern translated from slug flow to churn flow.

Correlations of the Holdup and the Frictional Pressure Drop in Air-Water Two-Phase Flow in a Flat Capillary Rectangular Channel

2004 ◽  
Author(s):  
Hideo Ide ◽  
Tohru Fukano
Keyword(s):  
Pressure Drop ◽  
Aspect Ratio ◽  
Two Phase Flow ◽  
Rectangular Channel ◽  
Flow Characteristics ◽  
Phase Flow ◽  
Two Phase Flows ◽  
Two Phase ◽  
Frictional Pressure Drop ◽  
Flow Phenomena

Both vertical upward and horizontal gas-liquid two-phase flows in a flat capillary rectangular channel were studied to clarify the flow phenomena, the holdup and the frictional pressure drop. The dimension of the channel used was 9.9 mm × 1.1 mm. The orientations of the channel were with the wide side vertical and the wide side horizontal. The differences between the flow characteristics in such orientations were investigated. New correlations of holdup and frictional pressure drop for flat capillary channels are proposed, in which the effect of aspect ratio has been taken into consideration.

scholarly journals Generalization of Martinelli-Nelson method of pressure drop calculation in two-phase flows

2017 ◽  
Vol 13 ◽  
pp. 02006 ◽  
Author(s):  
Marian Trela ◽  
Roman Kwidzinski ◽  
Marcin Lackowski
Keyword(s):  
Pressure Drop ◽  
Two Phase Flows ◽  
Two Phase

scholarly journals Calculations of the pressure drop in the natural circulation boiler evaporator

2018 ◽  
Vol 240 ◽  
pp. 05009 ◽  
Author(s):  
Slawomir Grądziel ◽  
Karol Majewski
Keyword(s):  
Pressure Drop ◽  
Power Plants ◽  
Graphical Method ◽  
Natural Circulation ◽  
Homogeneous Model ◽  
Phase Slip ◽  
Two Phase Flows ◽  
Two Phase ◽  
Pressure Losses

The paper presents different models used to determine pressure losses in two-phase flows: the homogeneous model, the Lockhart-Martinelli, the Friedel and the Chisholm phase-slip models and the Martinelli-Nelson graphical method. The pressure losses are calculated for the evaporator of an OP-210 boiler with the output of 210×103 kg/h operating in one of the Polish power plants. The results obtained by means of the presented models are compared to each other.

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